UC Museum of Paleontology

Despite the title, this is actually a research facility that's closed to the public. That said, the location within the Valley Life Sciences Building is fronted by an accessible atrium area that includes some cool fossil exhibits, including a life-size cast of a Tyrannosaurus rex skeleton. The Life Sciences building is usually open to the public from 9am to 10pm, but may be closed during holidays, weekends and parts of summer.